A variety of electronic devices include sliding covers that open and close sections to be blocked. In such devices, for example, the sections to be blocked are protected by retaining the sliding covers in a closed state when the devices are not in use, and the sections are exposed by changing the state of the sliding covers to an open state when the devices are in use. For example, digital cameras include sliding covers for opening and closing lens sections and strobe sections. The sliding covers are retained in the closed state so as to cover the lens sections and the strobe sections when the digital cameras are not in use, and the state of the sliding covers is changed to the open state to expose the lens sections and the strobe sections to the front when the digital cameras are in use.
Among such sliding covers, a sliding cover having two pinions (10, 11) that synchronously rotate and are respectively meshed with two parallel racks (4, 4) formed in a lens cover (2) so as to stabilize the amount of force required to open and close the lens cover (2) is disclosed in Japanese Unexamined Patent Application Publication No. 2000-305131. Moreover, in Japanese Unexamined Patent Application Publication No. 2000-305131, one end of a lever (14) is linked to an eccentric position of the pinion (10) so as to be rotatable, and a pin (15b) provided on the other end of the lever (14) is engaged with a cam groove formed in an optical device body (1) so as to be slidable. A coiled spring (19) is stretched between a hook (17) of the lever (14) and a hook (18) provided on the optical device body (1) to form toggling means. The toggling means biases the lens cover (2) in the closing direction when the lens cover (2) is located adjacent to the closed position, and biases in the opening direction when the lens cover (2) is located adjacent to the open position. The toggling means reverses the biasing direction at the midpoint of the slidable range of the lens cover (2).
In the lens cover (2) disclosed in Japanese Unexamined Patent Application Publication No. 2000-305131, a sliding force applied to any portions of the lens cover (2) is evenly transmitted to the two racks (4, 4) by the pinions (10, 11) that synchronously rotate. Thus, the opening and closing operations can be stabilized.
The lens cover (2) disclosed in Japanese Unexamined Patent Application Publication No. 2000-305131 has an advantage in that the amount of force for opening and closing can be stabilized. However, the overall structure cannot be made compact, and has poor assembling workability.
That is to say, members required to form the lens cover (2), such as a metal sheet (9) having the cam groove (16) and the hook (18), and the coiled spring (19), are provided on the optical device body (1). Therefore, the optical device body (1) requires spaces for disposing these members, thus increasing the size. Accordingly, the optical device body (1) cannot be reduced in size.
In addition, incorporation of the lens cover (2) into the optical device body (1) requires additional work operations such as fixing the metal sheet (9) to the optical device body (1) and engaging the pin (15b) provided on the other end of the lever (14) with the cam groove (16) of the metal sheet (9) so as to be slidable, and hanging both ends of the coiled spring (19) on the hook (17) of the lever (14) and the hook (18) of the metal sheet (9) while the coiled spring (19) is stretched. Therefore, it is time consuming to assemble the lens cover (2) into the optical device body (1), and this causes lower manufacturing efficiency and an increase in costs.